<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta http-equiv="X-UA-Compatible" content="IE=edge">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Document</title>
        <style>
            /*PC设备样式*/
            @media screen and (min-width:1000px){
                body{
                    background: #133452;
                }
            }
            /*平板设备样式*/
            @media screen and (max-width:1000px) and (min-width:600px){
                body{
                    background: #3878b4;
                }
            }
            /*移动设备样式*/
            @media screen and (max-width:600px) and (min-width:300px){
                body{
                    background: #8ac6ff;
                }
            }
        </style>
    </head>
    <body>

    </body>
</html>